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Re: using libmagic in Emacs?
From: |
joakim |
Subject: |
Re: using libmagic in Emacs? |
Date: |
Fri, 21 Aug 2009 19:38:15 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.1.50 (gnu/linux) |
New filemagic patch mostly fixing Eli:s concerns.
Eli Zaretskii <address@hidden> writes:
>> +DEFUN ("libmagic-file-internal", Flibmagic_file_internal,
>> Slibmagic_file_internal, 1,1,0,
>> + doc: /* Return (MIME_TYPE MIME_ENCODING DESCRIPTION) for
>> FILENAME_OR_BUFFER.
>> +Return nil on error. */)
Renamed entry point to libmagic-file-internal since its meant to be
of internal usage for a lisp wrapper, yet to be written. Should that be
a new file BTW?
> This doc string "needs work"(TM). Please use the doc string of
> visited-file-name as an example.
I worked on this
>
>> + (filename_or_buffer)
>> + Lisp_Object filename_or_buffer;
>
> Using a `_' in an argument is un-Lisp'y (IMO).
Ok.
> You need to encode file names before you pass them to C APIs. Use
> ENCODE_FILE to do that; see file-attributes for an example of how this
> is done.
Ok.
>> + if (rvs == NULL) goto libmagic_error;
>> + Lisp_Object file_mime = intern (rvs);
>
> You cannot declare variables in the middle of a block: Emacs does not
> require a C99 compiler yet and need to support C90 or even older
> compilers, which will reject this code.
I'm habing trouble remembering not to use c99. Is there some convenient
compiler flag to force lower versions? Fixed the errors I saw.
> Is file_encoding supposed to be a valid encoding, one of those for
> which Emacs has a coding-system? If so, perhaps you should make sure
> you indeed return a valid coding-system or its alias, or otherwise
> tell in the doc string that it's not guaranteed to be valid (so that
> the caller should validate it before using).
I described a bit more in the doc string. Ok?
diff --git a/configure.in b/configure.in
index f4096db..49a3f15 100644
--- a/configure.in
+++ b/configure.in
@@ -137,6 +137,8 @@ OPTION_DEFAULT_ON([xft],[don't use XFT for anti aliased
fonts])
OPTION_DEFAULT_ON([libotf],[don't use libotf for OpenType font support])
OPTION_DEFAULT_ON([m17n-flt],[don't use m17n-flt for text shaping])
+OPTION_DEFAULT_ON([libmagic],[don't compile with libmagic support])
+
OPTION_DEFAULT_ON([toolkit-scroll-bars],[don't use Motif or Xaw3d scroll bars])
OPTION_DEFAULT_ON([xaw3d],[don't use Xaw3d])
OPTION_DEFAULT_ON([xim],[don't use X11 XIM])
@@ -2223,6 +2225,19 @@ if test x"$ac_cv_func_alloca_works" != xyes; then
AC_MSG_ERROR( [a system implementation of alloca is required] )
fi
+
+HAVE_LIBMAGIC=no
+if test "${with_libmagic}" != "no"; then
+ #libmagic support
+ AC_CHECK_HEADERS(magic.h, [
AC_CHECK_LIB(magic,magic_open,HAVE_LIBMAGIC=yes) ])
+fi
+
+if test "${HAVE_LIBMAGIC}" = "yes"; then
+ LIBMAGIC=-lmagic
+ AC_SUBST(LIBMAGIC)
+ AC_DEFINE(HAVE_LIBMAGIC, 1, [Define to 1 if using libmagic.])
+fi
+
# fmod, logb, and frexp are found in -lm on most systems.
# On HPUX 9.01, -lm does not contain logb, so check for sqrt.
AC_CHECK_LIB(m, sqrt)
@@ -2954,6 +2969,7 @@ echo " Does Emacs use -lpng?
${HAVE_PNG}"
echo " Does Emacs use -lrsvg-2? ${HAVE_RSVG}"
echo " Does Emacs use -lgpm? ${HAVE_GPM}"
echo " Does Emacs use -ldbus? ${HAVE_DBUS}"
+echo " Does Emacs use -lmagic?
${HAVE_LIBMAGIC}"
echo " Does Emacs use -lfreetype?
${HAVE_FREETYPE}"
echo " Does Emacs use -lm17n-flt?
${HAVE_M17N_FLT}"
diff --git a/src/Makefile.in b/src/Makefile.in
index 425cf98..33d1a14 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -420,6 +420,7 @@ LIBX= $(LIBXMENU) LD_SWITCH_X_SITE
#endif /* not HAVE_LIBRESOLV */
LIBSOUND= @LIBSOUND@
+LIBMAGIC= @LIBMAGIC@
CFLAGS_SOUND= @CFLAGS_SOUND@
RSVG_LIBS= @RSVG_LIBS@
@@ -878,7 +879,7 @@ SOME_MACHINE_LISP = ../lisp/mouse.elc \
duplicated symbols. If the standard libraries were compiled
with GCC, we might need gnulib again after them. */
-LIBES = $(LOADLIBES) $(LIBS) $(LIBX) $(LIBSOUND) $(RSVG_LIBS) $(DBUS_LIBS) \
+LIBES = $(LOADLIBES) $(LIBS) $(LIBX) $(LIBSOUND) $(LIBMAGIC) $(RSVG_LIBS)
$(DBUS_LIBS) \
LIBGPM LIBRESOLV LIBS_SYSTEM LIBS_MACHINE LIBS_TERMCAP \
LIBS_DEBUG $(GETLOADAVG_LIBS) \
@FREETYPE_LIBS@ @FONTCONFIG_LIBS@ @LIBOTF_LIBS@ @M17N_FLT_LIBS@ \
diff --git a/src/fileio.c b/src/fileio.c
index 3702d4c..cbb0461 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -205,6 +205,10 @@ Lisp_Object Vdirectory_sep_char;
int write_region_inhibit_fsync;
#endif
+#ifdef HAVE_LIBMAGIC
+#include <magic.h>
+#endif
+
/* Non-zero means call move-file-to-trash in Fdelete_file or
Fdelete_directory. */
int delete_by_moving_to_trash;
@@ -2997,6 +3001,77 @@ DEFUN ("unix-sync", Funix_sync, Sunix_sync, 0, 0, "",
#endif /* HAVE_SYNC */
+#ifdef HAVE_LIBMAGIC
+DEFUN ("libmagic-file-internal", Flibmagic_file_internal,
Slibmagic_file_internal, 1,1,0,
+ doc: /* Return (MIME-TYPE MIME-ENCODING DESCRIPTION) for
+FILENAME-OR-BUFFER using libmagic. If FILENAME-OR-BUFFER is a file,
+return information about the file. If FILENAME-OR-BUFFER is a buffer,
+return information about the file of the buffer. MIME-TYPE and
+MIME-ENCODING are the mime type and mime encoding as determined by
+libmagic. DESCRIPTION is the human readable descripton offered by
+libmagic for the file.
+
+The default libmagic database is used, and the quality of information
+given depends on your version of that database. Often the mime type is
+less exact than the description.
+
+ */)
+ (filename_or_buffer)
+ Lisp_Object filename_or_buffer;
+{
+ CHECK_STRING_OR_BUFFER (filename_or_buffer);
+ magic_t cookie=NULL;
+ char* f = NULL;
+ const char* rvs;
+ Lisp_Object file_freetext;
+ Lisp_Object rv;
+ Lisp_Object file_mime;
+ Lisp_Object file_encoding;
+
+ Lisp_Object filename, absname, encoded_absname;
+ struct gcpro gcpro1;
+
+ GCPRO1 (f);
+
+ if (STRINGP (filename_or_buffer))
+ filename = filename_or_buffer;
+ if (BUFFERP (filename_or_buffer))
+ filename = XBUFFER (filename_or_buffer)->filename;
+ absname = Fexpand_file_name (filename, current_buffer->directory);
+ f = SDATA(ENCODE_FILE (absname));
+
+ cookie = magic_open (MAGIC_ERROR);
+ if (cookie == NULL) goto libmagic_error;
+ magic_load (cookie, NULL); /* load default database */
+
+ magic_setflags (cookie, MAGIC_MIME_TYPE | MAGIC_ERROR);
+ rvs = magic_file (cookie, f);
+ if (rvs == NULL) goto libmagic_error;
+ file_mime = intern (rvs);
+
+ magic_setflags (cookie, MAGIC_MIME_ENCODING | MAGIC_ERROR);
+ rvs=magic_file (cookie, f);
+ if (rvs == NULL) goto libmagic_error;
+ file_encoding = intern(rvs);
+
+ magic_setflags (cookie, MAGIC_NONE | MAGIC_ERROR);
+ rvs=magic_file (cookie, f);
+ if (rvs == NULL) goto libmagic_error;
+
+ file_freetext = build_string (rvs);
+ rv = Fcons (file_mime, Fcons (file_encoding, Fcons (file_freetext, Qnil)));
+
+ magic_close (cookie);
+ UNGCPRO;
+ return rv;
+ libmagic_error:
+ if (cookie != NULL) magic_close (cookie);
+ report_file_error("Libmagic error",Qnil);
+ UNGCPRO;
+ return Qnil;
+}
+#endif
+
DEFUN ("file-newer-than-file-p", Ffile_newer_than_file_p,
Sfile_newer_than_file_p, 2, 2, 0,
doc: /* Return t if file FILE1 is newer than file FILE2.
If FILE1 does not exist, the answer is nil;
@@ -5781,6 +5856,9 @@ When non-nil, the function `move-file-to-trash' will be
used by
#ifdef HAVE_SYNC
defsubr (&Sunix_sync);
#endif
+#ifdef HAVE_LIBMAGIC
+ defsubr (&Slibmagic_file_internal);
+#endif
}
/* arch-tag: 64ba3fd7-f844-4fb2-ba4b-427eb928786c
--
Joakim Verona
- Re: using libmagic in Emacs?, (continued)
- Re: using libmagic in Emacs?, Stephen J. Turnbull, 2009/08/20
- Re: using libmagic in Emacs?, Richard Stallman, 2009/08/20
- Re: using libmagic in Emacs?, Stefan Monnier, 2009/08/21
- Re: using libmagic in Emacs?, Stephen J. Turnbull, 2009/08/22
- Re: using libmagic in Emacs?, Stefan Monnier, 2009/08/22
- Re: using libmagic in Emacs?, Stefan Monnier, 2009/08/20
- Re: using libmagic in Emacs?, joakim, 2009/08/20
- Re: using libmagic in Emacs?, Andreas Schwab, 2009/08/20
- Re: using libmagic in Emacs?, joakim, 2009/08/21
- Re: using libmagic in Emacs?, Eli Zaretskii, 2009/08/21
- Re: using libmagic in Emacs?,
joakim <=
- Re: using libmagic in Emacs?, Rupert Swarbrick, 2009/08/21
- Re: using libmagic in Emacs?, Andreas Schwab, 2009/08/21
- RE: using libmagic in Emacs?, Drew Adams, 2009/08/21
- Re: using libmagic in Emacs?, Eli Zaretskii, 2009/08/21
- Re: using libmagic in Emacs?, joakim, 2009/08/21
- Re: using libmagic in Emacs?, Andreas Schwab, 2009/08/21
- Re: using libmagic in Emacs?, joakim, 2009/08/22
- Re: using libmagic in Emacs?, Ken Raeburn, 2009/08/22
- Re: using libmagic in Emacs?, joakim, 2009/08/23
- Re: using libmagic in Emacs?, Eli Zaretskii, 2009/08/23